Continuous spinning frame for the wetspinning of artificial yarns, in particular viscose rayon



G. DlOTTl 3,292,210

Dec. 20, 1966 commuous SPINNING FRAME FOR THE WET-SPINNING OF ARTIFICIAL YARNS, LN PARTICULAR VISCOSE RAYON 4 Sheets-Sheet L Filed July 22, 1964 Dec. 20, 1966 e. DIOTTI 3,292,210

coNTINUoUs SPINNING FRAME FOR THE WET-SPINNING OF ARTIFICIAL YARNS, IN PARTICULAR VISCOSE RAYON Filed July 22, 1964 4 Sheets-Sheet :1

Dec. 20, 1966 e. DlOTTl 2 CONTINUOUS SPINNING FRAME FOR THE WET-SPINNING OF ARTIFICIAL YARNS, IN PARTICULAR VISCOSE RAYON Filed July 22, 1964 4 Sheets-Sheet T'- Dec. 20, 1966 G. DIOTTI 3,292,210

CONTINUOUS SPINNING FRAME FOR THE WET-SPINNING OI" ARTIFICIAL YARNS, 1N PARTICULAR VISCOSE RAYON Filed July 22, 1964 4 Sheets-Sheet 7 .WA Ad 4 1;

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United States Patent 3,292,210 CONTINUOUS SPINNING FRAME FOR THE WET- SIINNING 0F ARTIFICIAL YARNS, IN PARTIC- ULAR VISCOSE RAYON Giaeinto Diotti, Milan, Italy, assignor to Studi e Brevetti ihglplicazioni Tessili S.R.l., Milan, Italy, a company of Filed July 22, 1964, Ser. No. 384,359 Claims priority, application Italy, July 26, 1963, Patent 703,414 Claims. (Cl. 18-8)- The present invention relates to a continuous spinning frame for wet-spinning artificial yarns, in particular cellulosic yarns, specially so-called viscose rayon.

There are known in the art, for instance in Italian Patent No. 516,501, continuous spinning frames wherein the threads (by the expression threads is herein intended the assembly of filaments issuing from an extrusion spinneret) are extruded from a spinneret, coagulated in a spinning bath, and subsequently gathered by an accumulation and forwarding device capable of contemporaneosuly treating a plurality of threads. As an example, in the cited patent there is described a continuous spinning frame that contemporaneously treats four threads. Numerous improvements of said spinning frame have since been realized.

The present invention concerns a continuous spinning frame wherein there is incorporated a device for accumulation and forwarding. Preferably said device is of the kind capable of contemporaneously treating more than one thread. By way of example, said device is illustrated as comprising a treating roll and a plurality, in particular four, forwarding rolls askew and successively spaced apart from the treating roll. Other accumulating and forwarding devices, preferably capable of contemporaneously forwarding a number of threads, may, however, be employed in embodying the present invention.

One object of the present invention is to permit spinning of yarns of viscose rayon with substantially complete elimination of the venomous exhalations that constitute a serious problem of this kind of spinning. Said exhalations require, if the necessary degree of hygiene and protection of workmen is to be achieved, with closed spinning frames. This, however, diminishes the accessibility of said spinning frames and renders their maintenance complicated. Moreover, since it is necessary to have access to the spinning frames from time to time, it is not possible to completely eliminate the exhalations.

The present invention also permits a particularly rational spinning with obtaining of yarns having particularly improved characteristics that are uniform and can be checked.

The spinning frame according to the present invention comprises, in combination with each spinneret and means for feeding to said spinneret the viscous solution to be spun, a substantially vertical conduit or pipe, within which the extruded filaments are drawn downwards by the bath, a substantially horizontal, drawing second conduit or pipe, hence substantially at right angle with respect to the first conduit, means for discharging the bath at the exit of said horizontal conduit or pipe, and an accumulating and forwarding device for lifting the thread separated from the bath, upwards, from said horizontal pipe or conduit, said accumulating and forwarding device being preferably associated with a plurality of spinnerets and, therefore, with a plurality of substantially vertical pipes and of substantially horizontal pipes.

Preferably the thread is lifted by the accumulating and forwarding device while passing through a section of vertical pipe or conduit, wherein the portion of the bath drawn along by the thread drips off and is discharged together with the main portion of the bath. The device is further characterized in that where the path of the thread passes from a vertical direction to a horizontal direction and vice versa, there are provided means for producing localized friction on the thread itself and, therefore, for localizing in said zones a substantial part of the stretch that the thread undergoes, in part by effect of the draw produced by the bath and in part by effect of the lift effected by the accumulating and forwarding device.

These and'other characteristics of the invention will be more fully understood from the description of a preferred example of embodiment, with reference to the appended figures, wherein FIG. 1 is a diagrammatic vertical section of a spinning frame unit built according to one embodiment of the invention; FIGURE 2 diagrammatically represents a horizontal section taken along the plane 22 of FIGURE 1, looking downwards, wherein are shown the guide and draw pipes associated with the threads lifted by the accumulating and forwarding device; FIGURE 3 is a diagrammatic sectional view in the plane 33 of FIG. 1 looking in the direction of the arrows, wherein are also shown the guide and draw pipes associated as a single accumulating and forwarding device; and FIGURES 4 and 5 illustrate on an enlarged scale two features of the device of FIGURE 1.

By spinning frame unit is intended in the foregoing just an accumulating and forwarding device with all the members associated therewith, it being obvious that an industrial spinning frame will comprise a plurality of such units in parallel.

In the example illustrated, one unit of the spinning frame comprises one single accumulating and forwarding device, four spinnerets and the conduits or pipings associated with said four spinnerets. Obviously an industrial spinning frame will comprise a plurality of such units in parallel: but for the sake of simplicity, for the purposes of the present description, also by the mere word spinning frame we shall intend a unit constructed as stated hereinbefore.

Now with reference to the appended figures, numeral 10 indicates a spinning pump which through piping 11 feeds a spinneret 12. Said spinneret is immersed in a spinning vat 13 filled with coagulating bath, and sustained in the desired position by any supporting member, not illustrated, that does not prevent the free flow of the bath. The coagulating bath penetrates into the vertical draw tube 14 and draws the thread, namely the bundle of filaments extruded from the spinneret along with it.

The thread and the bath, therefore, run through the vertical tube 14 and through an angular joint 15, illustrated on an enlarged scale in FIGURE 4, they penetrate into the horizontal tube 16.

At the end of tube 16 there is provided an angle joint 17, connected to the discharge 18 and to the collector 19, to be dealt with hereinafter, in correspondence with which is effected separation between the thread on one hand and on the other hand the coagulating bath, and the gases and vapours that are freed in the reaction between the viscose and the spinning bath. The coagulating bath fiows through said discharge 18 to said collector 19. The thread runs upwards through the guide tube 20 and is wound by the accumulating and forwarding device generally indicated by 21 and comprising a treating roll 22 and four forwarding rolls 23.

As can be seen in FIGURE 4, the thread and the bath, as well as also the gases and vapours, that come from the vertical dragging tube 14, leave the latter and pass through a nozzle 24 that might also be integral with the tube 14, but is preferably separated from it for easy assembling and maintenance, and because it is desirably constituted of different material. Said nozzle 24 has its lower end conically tapered and rests on an annular gasket 25 that in turn rests on a shoulder 26 of a joint generically indicated by numeral 27. Said annular gasket 25 prevents the bath from penetrating into the space between the nozzle 24 or the tube 14 and the joint 27. Said .joint 27 is shaped as an angular member and is provided in its upper portion, into which the tube 14 penetrates, with a gasket 28 and a threaded cap 29 for sealing.

In its lower portion the joint 27 provides a short horizontal conduit 30 into which the bath penetrates and from which said bath enters into the horizontal tube 16. The sealing in this zone of the joint 27 is also ensured by a gasket 31 and a sleeve 32. Preferably the joint 27 is of lead While the tube 14 and the tube 16 are prefer? ably of glass or of plastic material, such as for instance polyvinyl chloride or any other suitable material. Preferably the nozzle 24 is constructed of a material highly resistant to wear, having a hardness of 7.50 or more in the Mohs scale and having a low coefficient of friction, preferably about from 0.20 to 0.25. Materials suited for that purpose and having such characteristics are for instances Carborundum, zirconinum titanate, synthetic ceramic materials containing a high percentage of aluminum oxide and others.

FIGURE illustrates the passage of the thread from the horizontal tube 16 to a vertical conduit through which it arrives, separated from the bath, at the accumulating and forwarding device-21 (FIG. 1). The tube 16 penetrates into a joint 33, preferably of lead, the sealing being ensured here by a gasket 34 and a sleeve 35. At the end of the tube 16 there is applied a nozzle 36 similar to the nozzle 24 in both shape and material. Said nozzle is placed in such a way that its outlet orifice is approxi- I mately in register with the axis of a tubular portion 37 of the joint 33. The joint 33 is also connected or integral with a tubular discharge 18 curved downwards and opening into the collector 19.

One single collector 19 is advantageously employed not only for one spinning frame unit, but also for all the units placed in parallel and, therefore, for the complete industrial spinning frame. The collector 19 of course is provided with means of discharge at one end or placed elsewhere conveniently, which needs no illustration, through which the bath is discharged and can be taken out and can be circulated or recovered in any desired manner. Said closed discharge (preferably with hydraulic closure) is preferably held under slight suction for instance mm. waterby means of an aspirator draws off the gases and vapours which can be recovered in that way, since they have a concentration suficient to allow economical recovery.

The operation of the spinning frame described is as follows:

The filaments extrudedin a state that is still highly plastic, are drawn downwards by the bath into the tube 14 and in that travel stretching begins. Leaving the nozzle 24 to pass into the conduit 30 and the tube 16,

the thread describes a right angle and slides on the lip of the outlet mouth of the nozzle 24.

Owing to the hardness and to the coefiicient of friction of said nozzle, this is able to stand the friction of the thread for a very long time (more than one year). In any case said friction localized at that point causes stretching. In the tube 16 the thread keeps moving with the bath that flows by reason of the difference of level between the spinning vat 13 and the discharge 19. In this zone, however, there is also felt the drawing action of the accumulating and forwarding device 21. According to the speed of the latter and according to the speed of the bath, there may be in the tube 16 still an effect of drawing by the bath upon the thread, or vice versa the thread may have a speed greater than the bath. In both cases the stretching continues in this zone, though to a reduced extent, becoming nil only where the speeds of the thread and that of the bath are identical. At the forwarding device 21 and passes through the tube 20 to.

leave through a nozzle 38 quite similar to the :nozzles 24 and 36, and through a thread-guide 39 to the accumulating and forwarding device 21,.while a portion of the bath dragged along drips off and passes through the discharge 18 to the collector 19. The thread arrives at the accumulating and forwarding device and undergoes then all the further treatments for fixing, desulfurating, bleach-T ing, washing, drying etc. required for this type of working and which need no description because they do not form part of the invention.

Since the orifice of the nozzle 38 has small cross-section,

there is no possibility whatsoever for the gases developed by the spinning bath to become diffused in the room thereby polluting the atmosphere. This is further prevented by the fact that the discharge of the bath into 1 the collector 19 takes place, as said above, under slight therefore the surface of the fresh spinning bath in the vat 13. Said vat may be conveniently covered, but it should be noted that the development of toxic gases and vapours takes place in the falling spinning bath and in the immediate vicinity of the upper mouth of the tube 14 and within the tube 14 itself and said gases and vapours 1 In the .zone of the first contact between the viscose and the spinning 1 bath, the bath is continuously renewed and the development of toxic gases and vapours in the room, therefore,

are drawn along by the bath downwards.

is nil.

The entire movement of the bath, the coagulation of the yarn and the separation of the yarn from the bath therefore take place in closed conduits. In that way,

as said, the development of ex-halations from the bath is completely eliminated, and at the same time there takes place a perfect coagulation of the thread over the long path it covers together with the bath and an effective and controlled stretching by the cooperation of said path of the thread with the bath and of the localized zones of friction provided by the nozzles 24 and 36.

The tension and, therefore, the stretching of the thread.

varies with the varying of the speed of the spinning bath with respect to the speed of the thread and, therefore, it can be perfectly adjusted by varying the diameter of the outlet hole of the nozzles 24 and 36 in relationship: with the overall count of the thread, with the filament,

count and with the speed of warding device.

The device is extremely cheap, and of easy maintenance. The only parts subjected to wear are the nozzles 24 and 36 and to lesser degree the nozzle 38 and the threadguides, but apart from the fact that they. be made of the accumulating and forsuitable material, they can be rotated from time to time the flow rate of the liquid flowing downwardly through said duct and frictionally guiding the extruded viscose filament, a substantially horizontal second tubular duct.

having an inlet end connected to said lower end of said first duct and a liquid exhaust passage and second filament guide means at its outlet end, discharge duct means connected to said outlet end to exhaust said flowing liquid, and a vertical tubular passageway having its lower end located above said second guide means and having a closed connection therewith to receive and conduct the filament upwardly, and collecting means disposed to cause upward travel of the filament in said passageway and to collect the upwardly traveling filament while the said fiowing liquid is exhausted through said discharge duct means.

2. Apparatus for Wet-spinning artificial yarns as claimed in claim 1, wherein a collector is disposed below the level of said second horizontal duct to receive the liquid exhausting from said discharge duct.

3. Apparatus for wet-spinning artificial yarns as claimed in claim 1 wherein means for exerting friction on the filament are disposed in the zones where the filament passes from the vertical duct to the horizontal duct and where the filament passes from the horizontal duct to the vertical passageway, thereby localizing in said zones a substantial part of the stretching that the filament undergoes partly by effect of the downward flow of the bath liquid with the filament in said vertical duct, and partly by elfect of the upward pull on the filament of said collecting means.

4. Apparatus for Wet-spinning artificial yarns as claimed in claim 2, wherein a right angular joint connects said first vertical duct and said horizontal duct to eifect the guiding of the filament, and application of friction thereto, thereby to stretch the yarn.

5. Apparatus for wet-spinning artificial yarns as claimed in claim 1, wherein said vertical tubular passageway has an orifice at its upper end of small cross-section to fit the filament moving therethrough to said collecting means so as to prevent the gases developed by the spinning bath from escaping through said orifice.

6. Apparatus for wet-spinning artificial yarns as claimed in claim 5, wherein said tubular passageway is connected to said second horizontal duct by a right angular joint to effect guiding of the filament and application of friction thereto, thereby further to stretch the yarn.

7. Apparatus for wet-spinning artificial yarns as claimed in claim 6, wherein said collecting means includes means for drawing the filament through said ducts, joints, and passageway and for forwarding it.

8. Apparatus for wet-spinning artificial yarns as claimed in claim 2, wherein a right angular joint connects said first vertical duct and said horizontal duct to effect guiding of the filament, a nozzle is secured to the lower end of the vertical duct, and said nozzle penetrates one arm of said right-angular joint, and said horizontal tube penetrates the other arm of said joint, so that the filament slides on the lip of said nozzle in changing its direction of movement from vertical to horizontal, and sealing means is interposed between both tubes and said joint,

and a second joint connects said horizontal duct with said vertical passageway and with said collector, said horizontal-duct has a nozzle secured to it which penetrates said second joint, and sealing means is interposed between said horizontal tube and said joint.

9. Apparatus for wet-spinning yarns as claimed in claim 8 wherein said nozzles are made of a material resistant to wear and having a hardness of at least 7.5 on the Mohs scale and a coeflicient of friction between 0.20 and 0.25.

10. Apparatus for wet-spinning yarns as claimed in claim 9, wherein said joints are made of lead, and said nozzles are made of a material selected from the group consisting of Carborundum, zirconium titanate and synthetic ceramics containing a high percentage of aluminum oxide.

References Cited by the Examiner UNITED STATES PATENTS 2,131,409 9/1938 Nai l8--8 X 2,241,304 5/1941 Heywood et al 188 X 2,294,871 1/ 1942 Sellner. 2,587,619 3/1952 Hofmann. 3,094,742 6/1963 Rybick et a1 18-8 FOREIGN PATENTS 233,728 3/ 1964 Austria.

WILLIAM J. STEPHENSON, Primary Examiner. 

1. APPARATUS FOR WET-SPINNING ARTIFICIAL YARNS, COMPRISING SPINNERET MEANS FOR SUBSTANTIALLY VERTICALLY AND DOWNWARDLY EXTRUDING VISCOSE, COAGULATING LIQUID BATH CONTAINER MEANS SURROUNDING SAID SPINNERET MEANS AND IN WHICH SAID SPINNERET MEANS IS IMMERSED, A FIRST VERTICAL TUBULAR DUCT CO-AXIAL TO SAID SPINNERET MEANS AND HAVING ITS UPPER END CONNECTED TO THE BOTTOM OF SAID CONTAINER AND HAVING A THROAT CONNECTED TO ITS LOWER END TO CONTROL THE FLOW RATE OF THE LIQUID FLOWING DOWNWARDLY THROUGH SAID DUCT AND FRICTIONALLY GUIDING THE EXTRUDED VISCOSE FILAMENT, A SUBSTANTIALLY HORIZONTAL SECOND TUBULAR DUCT HAVING AN INLET END CONNECTED TO SAID LOWER END OF SAID FIRST DUCT AND A LIQUID EXHAUST PASSAGE AND SECOND FILAMENT GUIDE MEANS AT ITS OUTLET END, DISCHARGE DUCT MEANS CONNECTED TO SAID OUTLET END TO EXHAUST SAID FLOWING LIQUID AND A VERTICAL TUBULAR PASSAGEWAY HAVING ITS LOWER END LOCATED ABOVE SAID SECOND GUIDE MEANS AND HAVING A CLOSED CONNECTION THEREWITH TO RECEIVE AND CONDUCT THE FILAMENT UPWARDLY, AND COLLECTING MEANS DISPOSED TO CAUSE UPWARD TRAVEL OF THE FILAMENT IN SAID PASSAGEWAY AND TO COLLECT THE UPWARDLY TRAVELING FILAMENT WHILE THE SAID FLOWING LIQUID IS EXHAUSTED THROUGH SAID DISCHARGE DUCT MEANS. 